Adipose tissue slices were prepared from middle subcutaneous or perirenal adipose tissue excised from pigs of different ages (and obesity) and incubated with [U-14C]glucose. After incubation, the slices were fixed with osmium tetroxide and separated into diameter ranges of 20-63, 63-102, and 102-153 μm, respectively. Following determination of cell size and number, the fixed adipocytes were decolorized with H2O2 prior to quantification of glucose conversion to total lipid, glyceride fatty acids, glyceride-glycerol, and CO2. Glucose conversion to total lipid or CO2 was unaffected by the presence of purified porcine insulin (0, 10, 100, 1000, and 100000 μU/ml). Within animals, adipocytes of different sizes were not different with regard to insulin sensitivity. Within a weight (age) group, conversion of glucose to total lipid (insulin present) or to glyceride fatty acids and glyceride-glycerol (insulin absent) per cell was significantly greater in large adipocytes compared to small adipocytes, regardless of the group examined. With increasing weight or age, there was a markedly decreased conversion of glucose to total lipid and glyceride fatty acids among adipocytes of similar size within a cell-size fraction. The diminution in glucose metabolism was greater (as a percentage) in 20-63 μm adipocytes than for 63-102 or 102-153 μm adipocytes. However, for all cell-size fractions there was a marked decrease in glucose conversion to fatty acids. Glyceride-glycerol synthesis was impaired in adipocytes from older pigs, but the decrease wasx less than observed for glyceride fatty acid synthesis.
|Original language||English (US)|
|Number of pages||9|
|Journal||Journal of Lipid Research|
|State||Published - 1981|
All Science Journal Classification (ASJC) codes
- Cell Biology